This past weekend I ran my car in a 3 Hour enduro at Mosport. In preparing the car we decided to take out the 400 Fr, 275 rr spring set up (that would run 1:38's all day long with) and go back to a set up that we ran about 6 years ago 600 Fr, 400 Rr. We were trying to take advantage of the new aero and higher hp and new tires. Simply put, the car was terrible to drive with the new higher rate package on it.
The car twitched, bucked, bounced, sliding all over the place and it was extremely hard to modulate the brakes as the front tires would pretty much ignite when you tried to brake hard. Coming out of Turn 10 there is a bump at the apex that if you ran your line correctly you would hit it. The bounce was so bad that I would bounce my head off the roll cage about 2 times. I ended up using a modified rain line. Under high speed braking going into Turn 8, the back end would start to slide very easily and I had to limit my trail braking down to the first apex.
On the positive side, through Turns 1, 4 and 8 the car was extremely predictable and flat. I was able to carry a ton of speed through those corners. Overall, the car was about 4 seconds a lap slower than with the softer spring setup.
Just my observations from last weekend.